Control apparatus equipped with a relay

ABSTRACT

A control apparatus equipped with a relay, especially for automatic firing installations, wherein the armature of the relay carries a transmission element which acts upon a bank of contacts. The transmission element is pivotably supported at the armature and through the agency of a control or positioning element engaging with the transmission element is operatively connected with an actuation element serving for adjusting the transmission element.

Unite tates net Liidi 2,322,792 3,551,084 12/1970 Willson CONTROL APPARATUS EQUIPPED WITH A RELAY Inventor: Roger Liidi, Boppelsen, Switzerland Assignee: R. Liidi AG, Regensdorf, Switzerland Filed: July 9, 1971 Appl. No.: 161,203

Foreign Application Priority Data July 13, 1970 Switzerland ..l0608/70 [1.8. Ci. ..335/ 145, 317/94, 431/69 Int. Cl. .JHOlh 61/01 Field of Search ..335/ 145, 200, 270; 317/92, 93, 94; 431/69, 71

References Cited UNITED STATES PATENTS 6/1943 Deubel H: v.431/69 [451 Apr. 10, 1973 FOREIGN PATENTS OR APPLICATIONS 680,982 9/1939 Germany ..335/l45 Primary Examiner-Harold Broome Attorney-Werner W. Kleeman [57] ABSTRACT A control apparatus equipped with a relay, especially for automatic firing installations, wherein the armature of the relay carries a transmission element which acts upon a bank of contacts. The transmission element is pivotably supported at the armature and through the agency of a control or positioning element engaging with the transmission element is operatively connected with an actuation element serving for adjusting the transmission element.

8 Claims, 6 Drawing Figures PATENTED APR 1 973 SHEET 2 UF 3 PATENTEUAPR 1 0191s 3 7 7, 15

sum 3 OF 3 CONTROL APPARATUS EQUIPIED WITH A RELAY BACKGROUND OF THE INVENTION I The present invention relates to a new and improved control apparatus equipped with a relay, especially for automatic firing or furnace installations, wherein the armature of the relay carries a transmission element which acts upon a bank of contacts.

Relays are quite extensively known to the art and owing to their relative simplicity are oftentimes used in control and regulating circuits. Still in such circuits which contain a number of these relays such make up an essential proportion of the cost thereof. Therefore, attempts have been made through suitable design of the equipment to reduce the number of relays. However, certain limitations are encountered since generally the sequence of control operations which are staggered in time cannot be coordinated such that these control operations can be carried out by a lesser number of relays than the number of switching operations, and this is especially so if between the individual switching operations certain blocking or locking operations must become effective.

SUMMARY OF THE INVENTION It is a primary object of the present invention to provide an improved control apparatus equipped with a relay which effectively overcomes the aforementioned disadvantages associated with the prior art.

Another and more specific object of the present invention is to provide a new and improved control apparatus by means of which it is possible to coordinate at least two switching operations which are staggered in time for thepurpose of maintaining a proper sequential functional performance of such switching operations, without considerably altering the basic and simple construction of therelay.

A further significant object of this invention is to provide a novel construction of control apparatus equipped with a relay which considerably extends the economies of systems of this type.

Now, in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the invention contemplates the provision of a novel control apparatus of the previously mentioned type which is manifested by the features that the transmission element is pivotably supported at the armature of the relay, and through the agency of a control or positioning element engaging with the transmissionelement is operatively connected with an actuation element serving for adjusting the transmission element.

By virtue of this arrangement the transmission element can assume two positions for instance. In one position of the transmission element the signal of the control circuit can be transmitted to the bank of contacts, whereas in the other position, even if there is present a signal of the control circuit, the contact bank is not actuated.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:

FIG. 1 is a perspective view of a schematically illustrated relay containing a control or positioning element in its rest position and engaging with the transmission element;

FIG. 2 illustrates the relay of FIG. 1 in its operating position, wherein the relay has responded after actuating the positioning element;

FIG. 3 illustrates the relay of FIG. 1 wherein the positioning element has been actuated without response of the relay;

FIG. 4 illustrates the relay of FIG. 1 wherein the relay has responded prior to actuation of the positioning or control element;

FIG. 5 is a simplified circuit diagram of an automatic oilfiring installation utilizing the control apparatus of the invention; and

FIG. 6 is a schematic illustration of the mechanical transmission elements of the automatic firing installation depicted in FIG. 5.

DETAILED DESCRIPTION OF THE PREFERRED I EMBODIMENTS Describing now the drawings, in FIGS. 1 to 4 there is illustrated a preferred embodiment of the inventive control apparatus equipped with a relay, wherein there is illustrated a base 1 of optional design upon which there is mounted a relay F. Relay F essentially consists of a coil 2, an armature 8, a bank of contacts 3 and a transmission element 4.

In the embodiment under consideration the armature 8 is designed as a lever member having the two legs or arms 8a and 8b, the arm 8b carrying at its end a knife edge bearing 13. The transmission element 4 is pivotably supported by means of its knife edge 15 at the knife edge bearing 13. Attached to the lever arm 8b of the movable armature 8 is a web or bracket 16 which is located above the knife edge bearing 13 and serves as a stop for a first position of the transmission element 4. In the rest position illustrated in FIG. I the transmission element 4 bears by means of its extension 18 against this web 16.

The bank of contacts 3 encompasses the actual contact 19 which is to be actuated by the transmission element 4 as well as the metallic blades or springs 20. According to an important aspect of this development a positioning or control element 30 engages with the transmission element 4 of the relay F. Positioning element 30 embodies flexed arm members 32 and 34 and is formed of a relatively thin spring wire. This spring wire, apart from the flexed arms 32, 34 further contains the two flexed loops or bends 40 and 41 arranged intermediate the arms 32 and 34 as shown. Reference character 39 denotes the direction of movement of an actuation element B which operatively engages with the leg portion 32 of the positioning or control element 30 and which brings about a movement in the direction of the arrow 39' at the second leg portion or leg 34. In order that this movement can be carried out in the manner indicated the positioning element 30 is mounted .at a bearing 37 of a sheet metal holder 38 or the like. By virtue of the construction of the leg portion 34 so as to be associated with the two loops 40 and 41 there is prevented displacement of the positioning elemerit 30 while nonetheless ensuring for its movement to all sides.

The one end of the leg portion 34 is disposed in a bore 42 of the transmission element 4, while a tension spring 44 engages at one end with the loop 41 of the first leg portion 32 of this positioning element 30, the

bearing 13 and simultaneously into the first position against the web 16. Spring 44 essentially corresponds to the elastic or spring restraint of a conventional relay, at which typically a spiral spring, connected at one end to the armature, and at the other end to the sheet metal angle member of the magnetic circuit, safeguards against the falling back of the armature into its rest position. i

In FIG. 1 the relay F and the actuation element B are shown in their rest position. If, as illustrated in FIG. 2, the actuation element B is actuated prior to the relay F then initially the transmission element 4 is brought into its second position, that is, is loweredinto the operable region of the contact bank 3 and then the armature 8 attracted, so that switching of the contacts results. This corresponds to the operational positionv of the ap- Although the transmission element 4i s lowered into the second position, still no'switching ofthecontacts occurs. This condition can be, for instance, realized by the actuation element 13 in that it moves further and triggers a further contact, so that for instance the installation is shut down and an alarm signal released. In FIG. 4 the relay F is shown in its operative position, withouthowever the transmission element 4 first having been actuated by the actuation element B, that is, lowered into the second position. Even if the actuation of the actuation element B is still initiated somewhat late the'conta'cts can no longer be actuated since the transmission element 4 is held inthe second position by a stop 43 at one of the metal blades or springs 20. On the other hand, the element B can move further since the legs 32 and 34 of the positioning element 30 are resilient and, as previously explained, can actuate a further contact which shuts down the installation.

The maintenance of a certain sequence of the functional operation, as such has been illustrated in conjunction with FIGS. 1 to 4, with the aid of switching conditions stored at the transmission element 4 is of considerable importance with regard to automatic firing or furnace installations owing to the usually existing regulatory requirements of a governmental agency or the like concerned therewith. It is in this context that the. described relay F, provides a particularly advantageous environment of use which can be used for itself and specifically as a photorelay and still fulfills the necessary safety requirements.

Hence the use of the inventive control apparatus equipped with the novel relay construction of this invention will now be considered in conjunction with a schematic circuit diagram of an automatic oil firing or furnace installation, as depicted in FIG. 5, and wherein reference character Ph designates a phase line or conductor and reference character N the null conductor or line. Now as the main switch HS is switched in then through the agency of the switch b the combustion motor M is directly turned on and the ignition device Z through the agency of the switch f At the same time a bimetallic thermo-element B, corresponding to the actuation element of the embodiment of FIGS. 1 to 4 previously discussed, is heated up, this element controlling the preflushing and safety time. Then the switch b is switched by the bimetallic thermo-element B and as a result the fuel valve V is opened. Now the ignition occurs. As a result the photocell FZ is energized and the photorelay F, corresponding to the relay of the embodiment of FIGS. 1 to 4, is attracted. As a result both switches f, and f are actuated. Now switch f takes over the control signal for the fuel valve V, instead of the switch b, as discussed above, and by means of the switch f the bimetallic thermo element B is switched off so that it can cool and the switch b is again placed into its starting position.

7 Even in the case of disturbances a sequentially correct course of the functional operations is ensured. If no ignition occurs then the bimetallic thermo-element B continues to heat up further until, by virtue of actuation of the switch b the installation is shut down. In order to again place the installation into operation there is provided a resetting device RS. Thiscondition corresponds to the showing of FIG. 3. Since no ignition occurs the relay F is not switched. The disturbance indicator SA indicates, for instance visually'or acoustically, the shut down of the installation. 0n the other hand, if switching of the relay F occurs prior to ,termination of the pre-flushing time then the condition de picted in FIG. -4 arises. The transmission element 4 is blocked and no switching of the contact bank 3 or the switches )1, f occurs.

The bimetallic thermo-element B continues to therefore heat up further until, owing to actuation of the switch b the installation is shut down. In FIG. 5 there is illustrated in phantom or chain-dot lines the mechanical connections between the element B, relay F and the switches f, and f and indicated with the corresponding reference characters used in the arrangement of FIGS. 1 to 4. In order to preserve clarity in illustration the mechanical connections of the element B with the switches b, and b have been omitted, yet such can be seen by referring to FIG. 6.

Now in FIG. 6 the same reference characters have been essentially used for the same or analogous components as considered above in conjunction with FIGS. 1 to 5. It will be seen that the element B possesses a switching rod S by means of which it actuates the starting contact b and thereafter the positioning or control element 30. A releasing pawl K serves for releasing the contact b after the element B has moved through a certain path of travel,'in the event that the switch f is not interrupted. Owing to the arrangement of the positioning element 30 it is possible to store switching pulses at a relay and therefore to maintain a sequentially correct course of the functional operation. Instead of actuating the positioning or control element 30 by means of a bimetallic element B it is also possible to carry out actuation by means of a synchronous motor or another electro mechanical or mechanical transmitter.

The transmission element 4 can also be constructed such that it can assume intermediate positions, with which certain contact banks are operatively associated, which can be optionally actuated so that more than two time staggered switching operations can be coordinated.

While there is shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.

. What is claimed is:

1. A control apparatus, especially for automatic firing installations, comprising a relay and a mechanical actuating element, said relay having an armature, a bank of contacts and a transmission element carried and shifted by said armature and a bank of contacts operatively engaged by said transmission element, said transmission element being situated between said armature and said bank of contacts and being pivotably supported at the armature, said actuation element actuating a positioning element which is connected to the transmission element.

2. The control apparatus as defined in claim 1, further including means defining an elastic restraint for said positioning element, said elastic restraint producing an elastic force by means of which said transmission element is supported at said armature.

3. The control apparatus as defined in claim 2, wherein said actuation element is movable between a rest position and an operable position, said positioning element, during such time as said actuation element is in its rest position, bringing by means of the elastic force of its elastic restraint said transmission element into a first position in which it cannot actuate said bank of contacts upon actuation of the armature of said relay means.

4. The control apparatus as defined in claim 1, wherein said transmission element embodies knife means, said relay armature having means defining a knife edge bearing, said knife means of said transmission element engaging with said knife edge bearing means of said relay armature.

5. The control apparatus as defined in claim 1, wherein said transmission element is mounted for pivotal movement between a first position and a second position, web means for limiting pivotable movement of said transmission element when it assumes said first position, and stop means for limiting movement of said transmission element when it assumes said second position.

6. The control apparatus as defined in claim 1, wherein said transmission element assumes a number of intermediate positions in which there can be optionally actuated given contact banks.

7. The control apparatus as defined in claim 1, especially for controlling automatic furnace firing installations, and wherein said actuation element comprises a bimetallic element of an automatic furnace firing installation which determines the pre-flushing and safety times during the heating-up period of the furnace installation.

8. A control apparatus, especially for automatic firing installations, comprising a relay and a mechanical actuatin element, said relay having an armature, a bank 0 contacts and a transmission element carried and shifted by said armature and a bank of contacts operatively engaged by said transmission element, said transmission element being situated between said armature and said bank of contacts and being pivotably supported at the armature, said actuation element actuating a positioning element which is connected to the transmission element, means defining an elastic restraint for said positioning element, said positioning element being defined by an elastic angle lever having a pair of legs and mounted at a bearing means, the first leg of said elastic angle lever being mounted at said transmission element and the second leg being operably engageable with said actuation element, said elastic angle lever incorporating loop means at the region of said second leg, said elastic restraint engaging with said loop means at the region of said bearing means.

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1. A control apparatus, especially for automatic firing installations, comprising a relay and a mechanical actuating element, said relay having an armature, a bank of contacts and a transmission element carried and shifted by said armature and a bank of contacts operatively engaged by said transmission element, said transmission element being situated between said armature and said bank of contacts and being pivotably supported at the armature, said actuation element actuating a positioning element which is connected to the transmission element.
 2. The control apparatus as defined in claim 1, further including means defining an elastic restraint for said positioning element, said elastic restraint producing an elastic force by means of which said transmission element is supported at said armature.
 3. The control apparatus as defined in claim 2, wherein said actuation element is movable between a rest position and an operable position, said positioning element, during such time as said actuation element is in its rest position, bringing by means of the elastic force of its elastic restraint said transmission element into a first position in which iT cannot actuate said bank of contacts upon actuation of the armature of said relay means.
 4. The control apparatus as defined in claim 1, wherein said transmission element embodies knife means, said relay armature having means defining a knife edge bearing, said knife means of said transmission element engaging with said knife edge bearing means of said relay armature.
 5. The control apparatus as defined in claim 1, wherein said transmission element is mounted for pivotal movement between a first position and a second position, web means for limiting pivotable movement of said transmission element when it assumes said first position, and stop means for limiting movement of said transmission element when it assumes said second position.
 6. The control apparatus as defined in claim 1, wherein said transmission element assumes a number of intermediate positions in which there can be optionally actuated given contact banks.
 7. The control apparatus as defined in claim 1, especially for controlling automatic furnace firing installations, and wherein said actuation element comprises a bimetallic element of an automatic furnace firing installation which determines the pre-flushing and safety times during the heating-up period of the furnace installation.
 8. A control apparatus, especially for automatic firing installations, comprising a relay and a mechanical actuating element, said relay having an armature, a bank of contacts and a transmission element carried and shifted by said armature and a bank of contacts operatively engaged by said transmission element, said transmission element being situated between said armature and said bank of contacts and being pivotably supported at the armature, said actuation element actuating a positioning element which is connected to the transmission element, means defining an elastic restraint for said positioning element, said positioning element being defined by an elastic angle lever having a pair of legs and mounted at a bearing means, the first leg of said elastic angle lever being mounted at said transmission element and the second leg being operably engageable with said actuation element, said elastic angle lever incorporating loop means at the region of said second leg, said elastic restraint engaging with said loop means at the region of said bearing means. 